Opening Up Kernel-Bypass TCP Stacks

We have seen a surge of kernel-bypass network stacks with different design decisions for higher throughput and lower latency than the kernel stack, but how do they perform in comparison to each others in a variety of workload, given that modern stacks have to handle both bulk data transfers over multi-hundred gigabit Ethernet and small request-response messages that require low latency? We found that even representative kernel-bypass stacks have never been compared for a set of basic workloads, likely because of difficulty to run their implementation. This paper takes the first step towards answering that question by comparing six in-kernel or kernel-bypass stacks. We show that existing stacks cannot handle those workloads at the same time or lack generality. We then use those observations to discuss possible pathways towards practical kernel-bypass stacks.